Google Announced a lot more improvements on the ad review center which launched in back 2007 and it has been getting continued improvement through the years.
The most recent upgrade is in three fold:
(1) Ad Reviews Center Impressions-Based Progress Bar
(2) Ad Previews, Landing Pages & Quicker Blocking Access
(3) Ability To Block Visually Similar Ads Via Screenshot Upload
Ad Reviews Center Impressions-Based Progress Bar
Here is a picture in the progress bar, which explains the total coverage from the ads you have reviewed so far. This new feature informs you the percentage of ads you’ve got reviewed relative fo the total impressions on your site.
Ad Previews, Landing Pages & Quicker Blocking Access
You will have access to information on a specific ad simply by hovering over the creative and clicking on the magnifying glass in the bottom right corner:
Plus, you can click on the magnifying glass to preview the landing page:
Ability To Block Visually Similar Ads Via Screenshot Upload
This feature I did not see live yet inside my account but Google describes it as being a method of using Google’s Image Search feature to check and block visually similar ads by simly uploading a screenshot or logo, or seeking text in images.
Forum discussion at WebmasterWorld and Google+.